The eleven side chain positional isomers of amphetamine can be distinguished using a combination of color tests, thin-layer chromatography, and mass spectrometry. The primary amines, 1-phenylpropylamine and β-methylphenethylamine, exhibited chromatographic behavior similar to amphetamine but were readily differentiated using mass spectrometry. The mass spectra of N-methylphenethylamine was very similar to amphetamine, but using color tests and chromatography it was readily differentiated from amphetamine.